It is well known to employ pressurized canisters and other pressurized containers to deliver fragrances, de-odorizers and many other substances. It is also known to provide housings for temporarily accommodating such containers. Timers and other controls have been employed to control dispensing. The following patent documents illustrate systems believed to be representative of the current state of the prior art in this field: U.S. Pat. No. 7,815,074, issued Oct. 19, 2010, U.S. Pat. No. 7,854,354, issued Dec. 21, 2010, U.S. Pat. No. 7,631,783, issued Dec. 15, 2009, U.S. Pat. No. 7,299,951, issued Nov. 27, 2007, U.S. Pat. No. 6,318,600, issued Nov. 20, 2001, U.S. Pat. No. 5,193,557, issued Mar. 16, 1993, U.S. Pat. No. 4,789,083, issued Dec. 6, 1988, U.S. Pat. No. 4,615,476, issued Oct. 7, 1986, U.S. Pat. No. 4,171,776, issued Oct. 23, 1979, U.S. Pat. No. 4,111,338, issued Sep. 5, 1978, and Japanese Patent App. No. JP2003012062, dated Jun. 29, 2001.
Eachome Houseware (HK) Co., Ltd makes available a number of aerosol dispensers utilizing canister housings, timers and other controls, a movable front cover allowing access to the housing interior for replacing canisters.